last lines of the lightdm log
+14.76s] DEBUG: Greeter start session gnome
[+14.76s] DEBUG: Preparing 'gnome' session for user ubuntu
[+14.76s] WARNING: Failed to load session file : No such file or directory:
[+15.22s] DEBUG: Process 1075 closed communication channel
[+15.22s] DEBUG: Process 1075 exited with return value 0
[+15.22s] DEBUG: Greeter quit
[+15.22s] DEBUG: pam_close_session -> System error
[+15.22s] DEBUG: pam_setcred(PAM_DELETE_CRED) -> System error
[+15.22s] DEBUG: Ending ConsoleKit session 0ea4e853e8c337893cd244ea00000004-1309951768.416550-747441001
last lines of the lightdm log PAM_DELETE_ CRED) -> System error 93cd244ea000000 04-1309951768. 416550- 747441001
+14.76s] DEBUG: Greeter start session gnome
[+14.76s] DEBUG: Preparing 'gnome' session for user ubuntu
[+14.76s] WARNING: Failed to load session file : No such file or directory:
[+15.22s] DEBUG: Process 1075 closed communication channel
[+15.22s] DEBUG: Process 1075 exited with return value 0
[+15.22s] DEBUG: Greeter quit
[+15.22s] DEBUG: pam_close_session -> System error
[+15.22s] DEBUG: pam_setcred(
[+15.22s] DEBUG: Ending ConsoleKit session 0ea4e853e8c3378